Question

A study examined the link between sodium intake and blood pressure in children and adolescents

between the ages of 8 and 18. The mean systolic blood pressure (SBP) was 112.8 mm Hg among
the 636 study participants who were overweight or obese and consumed high levels of sodium,
resulting in a 95% confidence interval for this group of 110.7 to 114.9 mm Hg.
The numerical value of the margin of error for this confidence interval is____ mm Hg.

Answer 1

2.1 mmHg

Explanation:

The confidence is given by:

Mean ± margin of error

Confidence interval = (110.7 ; 114.9)

Mean = 112.8

Lower boundary = 110.7

Taking the lower boundary :

Lower boundary = mean - margin of error

110.7 = 112.8 - margin of error

Margin of Error = 112.8 - 110.7

Margin of Error = 2.1